1 68-0134
C.H. • 9-93 • ©Honeywell Inc. 1993 • Form Number 68-0134
The T8624C,D Chronotherm III Program-
mable Fuel Saver Thermostats provide auto-
matic control of multistage heating/cooling sys-
tems and offer users the highest standard of
comfort and convenience available with energy
savings.
■ Different schedules may be selected for week-
days, Saturday and Sunday.
■ Can be programmed in hand (with batteries in-
stalled) or on wall to provide up to four tempera-
ture settings per day.
■ Large digital clock (liquid crystal display) indi-
cates continuous time, day, current period and
room temperature.
■ Adaptive Intelligent Recovery™ brings room tem-
perature to programmed temperature at pro-
grammed time, maximizing comfort and energy
savings.
■ Temperature control program maintains tempera-
ture within 1° F of setpoint.
■ Temporary program override available by using:
—WARMER and COOLER keys.
—SKIP next period key.
—CHANGE to last period key.
■ HOLD TEMP key provided for indefinite pro-
gram override (vacation/holiday).
■ Installer self-test and time delay override save
installation time.
■ SYSTEM light-emitting diode (LED) indicates
system is energized.
■ Models available with automatic or manual heat/
cool changeover.
■ Batteries included provide power to maintain
clock and memory during power failures.
■ Switching subbase with wiring terminals included.
■ Powered directly from control transformer, re-
quiring an extra (24V) wire to thermostat.
■ Fan operation switch to select either independent
or direct thermostat control of fan in heating
included on back of select models.
CONTENTS
Specifications .................................................2
Ordering Information.....................................2
Selection/Application .....................................4
Installation .....................................................5
Checkout.......................................................11
Programming the Thermostat ......................14
Operating the Thermostat ............................18
Troubleshooting ...........................................21
Glossary ....................................................... 22
T8624C,D (5-1-1 Day
Programming) Chronotherm
®
III Fuel Saver Thermostats